title: Depression, anxiety-like behavior and memory impairment are associated with increased oxidative stress and inflammation in a rat model of social stress.
abstract: In the present study, we have examined the behavioral and biochemical effect of induction of psychological stress using a modified version of the resident-intruder model for social stress (social defeat). At the end of the social defeat protocol, body weights, food and water intake were recorded, depression and anxiety-like behaviors as well as memory function was examined. Biochemical analysis including oxidative stress measurement, inflammatory markers and other molecular parameters, critical to behavioral effects were examined. We observed a significant decrease in the body weight in the socially defeated rats as compared to the controls. Furthermore, social defeat increased anxiety-like behavior and caused memory impairment in rats (P<0.05). Socially defeated rats made significantly more errors in long term memory tests (P<0.05) as compared to control rats. Furthermore, brain extracellular signal-regulated kinase-1/2 (ERK1/2), and an inflammatory marker, interleukin (IL)-6 were activated (P<0.05), while the protein levels of glyoxalase (GLO)-1, glutathione reductase (GSR)-1, calcium/calmodulin-dependent protein kinase type (CAMK)-IV, cAMP-response-element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) were significantly less (P<0.05) in the hippocampus, but not in the prefrontal cortex and amygdala of socially defeated rats, when compared to control rats. We suggest that social defeat stress alters ERK1/2, IL-6, GLO1, GSR1, CAMKIV, CREB, and BDNF levels in specific brain areas, leading to oxidative stress-induced anxiety-depression-like behaviors and as well as memory impairment in rats.
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX 77204, USA.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Patki
authors.forename: Naimesh
authors.initials: N
authors.lastname: Solanki
authors.forename: Fatin
authors.initials: F
authors.lastname: Atrooz
authors.forename: Farida
authors.initials: F
authors.lastname: Allam
authors.forename: Samina
authors.initials: S
authors.lastname: Salim
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D003863:Depression / Q000378:metabolism; D004195:Disease Models, Animal; D007249:Inflammation; D008297:Male; D008569:Memory Disorders / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D012930:Social Dominance; D013315:Stress, Psychological / Q000378:metabolism*
keywords: Anxiety; BDNF; CAMKIV; ECL; ERK1/2; GLO-1; GSR; LE; Learning and memory and social defeat; Long-Evans; Oxidative stress: depression; P-CREB; PVDF; RAWM; SD; SDS-PAGE; SOD; SS; Sprague Dawley; T-CREB; brain derived neurotrophic factor; calcium/calmodulin-dependent protein kinase type IV; enhanced chemiluminescence; extracellular signal-regulated kinase-1/2; glutathione reductase-1; glyoxalase-1; phospho-cAMP response element–binding protein; polyvinyledene difluoride; radial arm water maze; social stressed; sodium dodecyl sulfate polyacrylamide gel electrophoresis; superoxide dismutase; total-cAMP response element–binding protein